I don't know enough about either to comment on it (I intend to check out both though), but I get the feeling Ufotable would secure interest in the series if they animated hollow ataraxia first, since it's also in the line of the current fate universe they've animated so far (zero, stay night). Since Apocrypha is a more standalone title it'd be better if it had enough interest from the series prior to being animated. The Fate series does have a lot of renown, but still a lot of viewers tend to overlook it (though if Heaven's Feel is done well enough that would actually probably be enough to boost it higher alone provided people decide to watch it to begin with, because Heaven's Feel is fantastic)
Also Lancer in those hawaiian-looking clothes yes